The New York City mayor, who sees himself as a progressive champion, started this primary season with dreams of becoming a Democratic kingmaker, very publicly withholding his endorsement of Hillary Clinton for six months in a bid to move her left on a number of issues important to progressives. He even attempted to organize a forum on inequality in Iowa, to which not a single candidate agreed to participate. He ended up endorsing Clinton anyway, just before Bernie Sanders’s revolution really took off, and for his disloyalty he was banished to the Iowa hinterlands to canvas for votes. He did make one high-profile appearance with Clinton, at New York’s Inner Circle dinner in April, but this was ruined by an unfortunate skit about “C.P. time.” He has now received his final reward: a speaking slot on the third day of the Democratic National Convention between 4 p.m. and 6 p.m. Eastern Time. His predecessor, meanwhile, who is not even a Democrat, is expected to speak in prime-time later tonight. Other notables who made the evening program include Sigourney Weaver and the mayors of Atlanta and Detroit. Better luck in 2020, Mr. Mayor.